The synthesis and pressure sensitive adhesive properties of acrylic copolymer latexes with different particle sizes

A series of acrylic copolymer latexes with different particle sizes and distribution were prepared by semi-continuous emulsion polymerization. Dynamic light scattering (DLS) was used to monitor the particle diameters, which shows that the particles have grown without significant secondary nucleation. The particle size of the latexes has decreased and the dynamic viscosity of the latexes has increased with the growing content of the surfactant at the seed stage. Dynamic mechanical analysis was used to characterize the molecular movement of the copolymers. Adhesive properties measured are loop tack force, peel strength and shear resistance according to FINAT test methods. For the two component latex system, the loop tack increases with the addition of small particle size latexes, while the shear strength decreases. For the three component latex, the peel force decreases.